CN213546383U

CN213546383U - Lithium ion battery roll core

Info

Publication number: CN213546383U
Application number: CN202021980059.9U
Authority: CN
Inventors: 林俊颇; 林俊仰; 朱孟; 赵玉楠
Original assignee: Zhongshan Tianmao Battery Co Ltd
Current assignee: Zhongshan Tianmao Battery Co Ltd
Priority date: 2020-09-11
Filing date: 2020-09-11
Publication date: 2021-06-25
Anticipated expiration: 2030-09-11

Abstract

The utility model relates to a lithium ion battery rolls up core, include: the positive plate and the negative plate comprise current collectors and active substances coated on the surfaces of the current collectors; the positive electrode of the current collector is an aluminum foil, and the negative electrode of the current collector is a copper foil; the positive electrode of the active material is lithium cobaltate or nickel cobalt lithium manganate, the negative electrode is graphite, a blank area is arranged on the current collector, the blank area is positioned in the middle of the pole piece in the length direction, and a tab is welded on the blank area; the blank area is rectangular, has no coating material and has the size of 10mm to 30 mm. The utility model discloses utmost point ear welding has reduced the distance that the electric current flowed in on the mass flow body at pole piece length direction's intermediate position, and at electrode width regularly, the internal resistance of mass flow body is directly proportional with length, and utmost point ear is located the centre, and the internal resistance of mass flow body is 1/4 of utmost point ear when one side, can reduce the internal resistance of electric core effectively, and then has reduced the big multiplying power discharge temperature rise of battery.

Description

Lithium ion battery roll core

Technical Field

The utility model relates to a lithium ion battery especially relates to a lithium ion battery rolls up core.

Background

In recent years, with the popularization of mobile internet devices such as smart phones and notebook computers, the popularization of electric vehicles such as electric bicycles and electric motorcycles, and the development of aerospace technologies such as unmanned aerial vehicles and space detectors, people have higher and higher performance requirements on various aspects of lithium ion batteries, and especially power lithium batteries charged and discharged with large current and high rate are expected by more people. At present coiling formula lithium ion battery electricity core structure welds the one end at aluminium and copper mass flow body with aluminium utmost point ear and nickel utmost point ear usually, and welding size ability accurate control like this, and the clearance accuracy requirement to the pole piece is lower, convenient operation, but according to joule law, internal resistance and length are directly proportional, and utmost point ear is great at the mass flow body internal resistance of one side, is unfavorable for big multiplying power charge-discharge.

Disclosure of Invention

The utility model aims at providing a lithium ion battery rolls up core to above-mentioned problem exactly. The battery has the characteristics of small internal resistance and low temperature rise during high-rate charge and discharge.

The utility model adopts the technical proposal that: a lithium ion battery jelly roll, comprising: the positive plate, the negative plate and the diaphragm are wound into a winding core; the positive plate and the negative plate comprise current collectors and active substances coated on the surfaces of the current collectors; the positive electrode of the current collector is an aluminum foil, and the negative electrode of the current collector is a copper foil; the positive electrode of the active material is lithium cobaltate or nickel cobalt lithium manganate, the negative electrode is graphite, a blank area is arranged on the current collector, the blank area is positioned in the middle of the pole piece in the length direction, and a tab is welded on the blank area; the blank area is rectangular, has no coating material and has the size of 10-30 mm.

The width of the tab is between 3 and 8 millimeters.

Compared with the prior art, the utility model has the advantages of as follows:

the utility model discloses utmost point ear welding has reduced the distance that the electric current flowed in on the mass flow body at pole piece length direction's intermediate position, and at electrode width regularly, the internal resistance of mass flow body is directly proportional with length, and utmost point ear is located the centre, and the internal resistance of mass flow body is the fourth of utmost point ear when one side, can reduce the internal resistance of electric core effectively, and then has reduced the big multiplying power discharge temperature rise of battery.

Drawings

Fig. 1 is the schematic diagram of the lithium ion battery positive plate after expansion.

Fig. 2 is the schematic diagram of the lithium ion battery positive plate after expansion.

Fig. 3 is a schematic diagram comparing the discharging temperature rise of the lithium ion battery with the existing battery.

Detailed Description

As shown in fig. 1 and fig. 2, the present invention includes: the positive plate 1, the negative plate 2 and the diaphragm are wound into a winding core; the anode plate comprises an anode plate current collector and an anode plate active substance coated on the surface of the current collector, wherein the anode of the anode plate current collector is an aluminum foil, the active substance 12 lithium or nickel cobalt lithium manganate of the anode plate is arranged on the anode plate current collector, a blank area 11 of the anode is reserved in a mode of eliminating the active substance coating after intermittent coating or continuous coating, the blank area is an area without the active substance coating, as shown in figure 1, the area is an area exposing the aluminum foil of the anode plate current collector, and an anode tab 13 can be welded after exposing the anode plate current collector, the cathode plate comprises a cathode plate current collector and a cathode plate active substance 22 coated on the surface of the current collector is a copper foil, the cathode plate active substance is graphite, a blank area 21 of the cathode is reserved on the cathode plate current collector in a mode of eliminating the active substance coating after intermittent coating or continuous coating, and the blank area is an, the region where the negative electrode tab current collector is exposed as shown in fig. 2 is exposed, and the negative electrode tab 23 can be welded. The blank area is located the middle position of pole piece length direction, length direction is the middle area of pole piece length direction after expanding. A tab is welded on the blank area; the blank area is rectangular, has no coating material, and has a width dimension of 10-30 mm. The width of the tab is between 3 and 8 millimeters.

As shown in fig. 3, the upper curve represents the temperature rise curve of the tab located at one side, the lower curve represents the temperature rise curve of the tab located at the middle, and it can be seen from the two curves that the temperature rise of the battery cell located at the middle along with the tab in the process of high-rate discharge is obviously improved, so that the problem of heat generation in the use process of the battery cell can be improved, and the service life of the battery cell is prolonged. Through optimizing utmost point ear structure, can reduce the battery internal resistance of assembling, reduced the inside ohmic polarization of battery, and then reduced the big multiplying power discharge temperature rise of battery.

Claims

1. A lithium ion battery jelly roll, comprising: the positive plate, the negative plate and the diaphragm are wound into a winding core; the positive plate and the negative plate comprise current collectors and active substances coated on the surfaces of the current collectors; the positive electrode of the current collector is an aluminum foil, and the negative electrode of the current collector is a copper foil; the positive electrode of the active material is lithium cobaltate or lithium nickel cobalt manganese oxide, and the negative electrode is graphite, and the lithium nickel cobalt manganese oxide lithium battery is characterized in that: a blank area is arranged on the current collector and is positioned in the middle of the pole piece in the length direction, and a tab is welded on the blank area; the blank area is rectangular, has no coating material and has the size of 10mm to 30 mm.

2. The lithium ion battery roll core of claim 1, characterized in that: the width of the tab is between 3mm and 8 mm.